The present invention relates to brake systems for motorcycles, and more particularly to methods of filling brake systems for motorcycles.
Typical motorcycle brake systems include a master cylinder assembly, a caliper assembly, and a brake line coupling the master cylinder assembly to the caliper assembly. Actuation of a hand lever of the master cylinder assembly pressurizes brake fluid through the brake lines and into the caliper assembly to press brake pads of the caliper assembly against a wheel rotor to slow or stop the rotation of the wheel. The master cylinder assembly includes a reservoir that contains the brake fluid supplied to the brake system.
For the brake system to work properly, the entire brake system must be filled with the brake fluid, except for some allowable air at the top of the reservoir. It is known to fill the brake system with fluid by removing a cover of the master cylinder assembly, filling the reservoir with brake fluid, opening a bleeder fitting located on the caliper assembly, pumping the brake lever until the fluid exits the bleeder fitting, and adding fluid to the reservoir as needed. When full, the cover is replaced and the bleeder fitting is closed. This process is time consuming and is not desirable for mass production.
In production, the fill process is performed after the brake system is attached to the motorcycle. Another known fill process used in this environment is to remove the cover, attached an adapter to the reservoir, use the adapter to evacuate the air from the brake system through the reservoir, use the adapter to fill the brake system with brake fluid through the reservoir, remove the adapter exposing the fluid within the reservoir, and replacing the cover onto the housing to seal the reservoir. The bleeder fitting remains closed throughout the entire process.
Other processes fill brake fluid from the bleeder fitting. In this process, the cover is removed, the bleeder fitting is opened, an adapter is attached to the bleeder fitting, the adapter passes brake fluid through the bleeder fitting to fill the brake system, the cover is replaced, the adapter is removed, and the bleeder fitting is closed.
These known fill processes generally have used either Dot 3, Dot 4, or Dot 5 brake fluid. Due to fluid characteristics required by modern antilock braking systems, Dot 4 brake fluid is becoming more common. Dot 4 brake fluid is more corrosive than Dot 5 brake fluid and has the potential to damage the cosmetic appearance of certain components of the motorcycle, such as the painted tank, if spilled or splashed. Because of this potential for cosmetic damage, the known fill processes that fill the brake system with the cover removed from the housing are disadvantageous. In addition, it is time consuming to remove and replace the cover during the fill process increasing process cycle times and the manufacturing expense of the motorcycle.